The graphical user interface of Cubase 10 has been thoroughly reworked.
Therefore, unfortunately, Cubase 10 cannot inherit Color Schemes and Custom Color settings made with previous Cubase versions on a system.
Cubase 10 will open with its default Color Scheme, which can be customized in Cubase's preferences (Windows: 'Edit' menu, macOS: 'Cubase' menu) under 'User Interface'.
Furthermore, Color Schemes saved as part of Preferences Presets or Profiles with previous Cubase versions cannot be restored in Cubase 10.